1.2 Flashcards
What is Newton’s first law of motion?
when external forces are balanced, an object will remain at rest or continue moving at a constant speed in a straight line.
What is Newton’s second law of motion?
When external forces acting on an object are unbalanced, the object accelerates in the direction of the unblanced force. This is summarised by the equation: F = ma
What is Newton’s third law of motion?
Every action has an equal and opposite reaction. So when two objects interact, they apply forces to one-another that are of equal magnitude and are in the opposite direction from one another.
What is the definiton of a Newton?
One Newton is the size of the unbalanced (resultant) force which will cause an object of mass 1kg to accelerate at 1ms^-1.
Break down the equation F = ma
F = unbalanced force (N)
m = mass (kg)
a = acceleration (ms^-2)
What is weight?
the force acting on an object due to gravity
Break down the equation W = mg
W = weight (N)
m = mass (kg)
g = gravitational field strength (Nkg^-1)
Describe friction
the force that opposes motion. This occurs between solid surfaces, liquids and within the air, causing air resistance
Describe free-fall and terminal velocity
Free-fall is the motion of an object where only the forces of weight and friction are acting upon it.
Terminal velocity occurs when a maximum velocity is reached, where the force of air resistance is balanced with the force of weight. As these forces are balanced, there is no acceleration and so terminal velocity is reached.
What is the gravitational field strength on Earth?
9.8 Nkg^-1
What is tension?
the pushing/pulling force excreted by each end of an object
How do you calculate tension?
F = ma
How do you calculate the magnitude of the resultant vector?
a^2 = b^2 + c^2
Calculate the direction of the resultant vector
tanx = opposite/adjacent
How do you calculate the vertical component of the given vector?
Fv = Fsinx
